1. Field of the Invention
The invention pertains to signal in noise detection particularly with respect to signal detection apparatus having a CFAR detection characteristic.
2. Description of the Prior Art
The estimator-correlator signal receiver device for detecting a noise like signal in a noise background is known in the prior art. Specifically, such estimator-correlators provide optimal detection of the presence of a gaussian random signal against a gaussian noise background. Such an estimator-correlator arrangement is disclosed in FIG. 7.11-4 of the textbook "Radar Detection" by J. V. DiFranco and W. L. Rubin, Prentice-Hall, Inc., Englewood Cliffs, N. J., 1968. Further references to the estimator-correlator may be had in the paper "Optimum Detection of Random Signals in Noise, with Application to Scatter-Multipath Communication, I" by Robert Price in the IRE Transactions on Information Theory, December 1956, page 125, in the paper "A Communication Technique for Multipath Channels" by R. Price and P. E. Green in the Proceedings of the IRE, Vol. 46, No. 3, March, 1958, page 555, and in U.S. Pat. No. 2,982,853, issued on May 2, 1961 to R. Price, et al entitled "Anti-Multipath Receiving System". The false alarm rate for such devices is typically a function of the background noise level, as well as of the setting of the detection output threshold. For reasons well appreciated in the art, it would be desirable to impart a constant false alarm rate (CFAR) characteristic to the circuit.